What Is the Difference between “Safety” and “Liveness” in a Consensus Protocol?

Safety ensures that all honest nodes agree on the same sequence of transactions and that committed transactions are final and will never be reversed. It means "nothing bad happens." Liveness ensures that the system continues to process new transactions and that honest nodes will eventually agree on a new block.

It means "something good eventually happens." Both are critical properties, but some protocols may prioritize one over the other under specific failure conditions.